Added alternative example

[julkue]

Here you go.
Closes #19

[julkue]

Ping @jbr

[jbr]

@julmot What improvement over the existing demo does the codepen demo offer? Could the existing demo be improved or replaced?

[jbr]

I would happily accept changes to https://github.com/jbr/jQuery.highlightRegex/blob/master/index.html if there are features that would improve it

[julkue]

Feel free to PR a link to that url to the README

what's wrong now?

[julkue]

1. It is responsive
2. It is colorized
3. It allows users to enter custom modifiers
4. It allows users to specify custom options

[jbr]

I realized there was no reason to have two similar examples. I'd like to replace index.html with something like yours, if you think those four improvements would help people get a sense of the plugin.

[julkue]

Well, I think both examples give a quick overview and beside of more options the CodePen demo offers a better UX.
So the choice is yours 😄